{"product_id":"1746-a4-allen-bradley-slc-500-4-slots-chassis","title":"1746-A4 | Allen Bradley | SLC 500 4 Slots Chassis","description":"\u003ch2\u003eAllen‑Bradley 1746‑A4 SLC 500 4‑Slot Chassis\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen‑Bradley 1746‑A4\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1746‑A4\u003c\/strong\u003e chassis, serves as the primary 4‑slot mechanical and electrical backplane frame used to house SLC 500 PLC and I\/O modules across 1746\/1747 system platforms. It provides fixed backplane power distribution, module seating alignment, and signal‑bus continuity for installed modules.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003ctd\u003e1746‑A4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eAllen‑Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOrigin\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDimensions\u003c\/th\u003e\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOperating Temp\u003c\/th\u003e\n\u003ctd\u003e0 to 60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower Consumption\u003c\/th\u003e\n\u003ctd\u003eNot applicable (passive chassis)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct Type\u003c\/th\u003e\n\u003ctd\u003ePLC Chassis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSeries\u003c\/th\u003e\n\u003ctd\u003eSLC 500 (1746\/1747)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Slots\u003c\/th\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eStorage Temp\u003c\/th\u003e\n\u003ctd\u003e-40 to +85 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRelative Humidity\u003c\/th\u003e\n\u003ctd\u003e5–95% RH noncondensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eComponent Type\u003c\/th\u003e\n\u003ctd\u003ePLC \u0026amp; I\/O chassis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Bus Communication Velocity Licenses\u003c\/h3\u003e\n\u003cp\u003eThe 1746‑A4 chassis supports deterministic backplane communication used in SLC 500 architectures. Each slot maintains fixed electrical spacing and impedance to ensure predictable scan‑cycle timing for analog, digital, and specialty modules. I\/O density scaling is preserved by maintaining uniform bus propagation delay across all four slots. Firmware flash compatibility resides entirely within the installed CPU or I\/O modules; the chassis itself contains no programmable logic and provides stable passive connectivity.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can modules be inserted or removed while the chassis is energized? A: No. SLC 500 modules require de‑energized conditions to avoid backplane faults.\u003c\/p\u003e\n\u003cp\u003eQ: Does the chassis impose current limits on installed modules? A: No. Current limits are defined by the connected power supply; the chassis only provides mechanical seating and bus continuity.\u003c\/p\u003e\n\u003cp\u003eQ: Are Series B and Series C modules compatible with the 1746‑A4? A: Yes. The chassis supports standard SLC 500 module families across multiple series revisions.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMount the chassis securely to reduce vibration and maintain backplane alignment.\u003c\/li\u003e\n\u003cli\u003eRoute high‑energy wiring separately from low‑level signal conductors to reduce noise coupling.\u003c\/li\u003e\n\u003cli\u003eEnsure modules are fully seated to avoid intermittent backplane contact.\u003c\/li\u003e\n\u003cli\u003eMaintain adequate ventilation around the chassis to support module thermal dissipation.\u003c\/li\u003e\n\u003cli\u003eFollow grounding and shielding practices per Allen‑Bradley wiring guidelines.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":48225303888062,"sku":"1746-A4","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0725\/1145\/5422\/files\/allen-bradley-1746-p2-slc-rack-mounting-power-supply-ygr5xlfmnmw_439654aa-af92-4ab5-aa41-e990822e19ae.png?v=1759030244","url":"https:\/\/www.autooiltech.com\/ar\/products\/1746-a4-allen-bradley-slc-500-4-slots-chassis","provider":"AutoOilTech Limited","version":"1.0","type":"link"}